Twitter hasn’t been having a very good time of it lately: turmoil in the
company’s executive ranks — including the recent departure of the chief
operating officer and the head of Twitter’s media unit — has raised concerns
about deeper issues and the service’s lackluster growth.

But the
real-time information network has other fires to put out as well,
including a fear that the company’s global and financial ambitions may
be stifling its previous commitment to free speech.